SafePlants

False Oat-grass (Arrhenatherum elatius)

Arrhenatherum elatius, commonly known as false oat-grass, tall oat-grass, tall meadow oat, onion couch, and tuber oat-grass, is a perennial grass species. It's a tall, fluffy-looking grass found in grasslands, roadside verges, and disturbed grounds.

Considerations for Pets

• The text mentions that oat grass "is fine for tortoises," but specifically warns not to confuse it with Tall Oat Grass/False Oat Grass (Arrhenatherum elatius). This implies there might be a distinction in suitability for tortoises between different types of oat grass.

Nomenclature and Taxonomy

• Scientific Name: Arrhenatherum elatius
• Synonyms: Arrhenatherum elatius (L.) Presl; Arrhenatherum elatius (L.) Beauv. ex J.&amp K. Presl; Arrhenathenum elatius L. (misspelling)
• Family: Poaceae (implied by being a grass)
• Genus: Arrhenatherum (comprising approximately six species native to temperate Europe and Asia)
• Taxonomic Rank: Two subspecies are mentioned.

Distribution and Habitat

• Native to temperate Europe and Asia.
• Introduced to the United States.
• Found in grasslands, roadside verges, and disturbed grounds.
• Specific locations mentioned: Willamette Valley, Columbia River Gorge, Ojdula (Transylvania, Romania), Germany

Ecological Role

• Considered invasive in some parts of the United States (CA, OR, TN, VA, WA).

Morphological Characteristics

• Perennial grass.
• Loosely-tufted grass with erect, smooth stems.
• Stems can reach 28-70 inches tall.
• Stems are occasionally bulblike at the base.
• Leaf blades are flat.
• Tussock-forming growth habit.
• Strongly upright growth.
• Plants do not spread by rhizomes, rather they grow in tufts.

Quirky Facts

• The stems are "occasionally bulblike at the base," giving it one of its common names: Onion Couch.
• One subspecies possesses corms while the other does not.

Interactions with Other Organisms

• Can host the Tall oatgrass mosaic virus (TOgMV), a novel member of the genus Tritimovirus.
• Observed with a Red-and-White Spider (Enoplognat species) on a blooming spikelet.
• Can affect seed yield losses in dry peas when growing as a volunteer plant.

Additional Information

• USDA PLANTS Database (Symbol: AREL3)
• Invasive Species Most Unwanted list.
• ResearchGate professional network for scientists.